Method of rolling zinc



Patented Feb. 1, 1927.

U N ITED S TA TiES 1,616,033 P ATENT OFF 1 CE OSCAR GERLACI-I, OF LA. SALLE, ZLL'INOIS, ASSIGNOR TO 'MATTI'IIESSEN IIEGELEE ZINC 00., A CORPORATION OF ILLINOIS.

METHOD OF ROLLING ZINC.

No Drawing.

This invention relates to a new and useful improvement in the method of rolling sheet zinc, and although peculiarly adapted to the rolling of this particular metal, is not- 5 to be understood as limited in this respect as it may be advantageously applied to the rolling of .any other metal which is ductile enough to be rolled into thin sheets or plates.

In the rolling of sheet zinc, it sometimes happens that the zinc sticks to the rolls and is thereupon drawn around with the roll and instead of being turned out in a thin, flat sheet follows the roll around necessitating the stoppage of the machine and the extrication of the sheet and thereby results in great inconvenience, loss of time and even danger to the rolling machine and its operators.

Heretofore, in order to prevent the sticking of the sheet zinc orthe rolls during the rolling operation, tallow was employed on the rolls, being applied thereto in a very thin sheet or layer. The heat of the rolls is suflicient to melt the tallow when it comes in contact with the same. However, a great disadvantage resulting from the use of tallow lay in the fact that whenever the sheet zinc was to be painted or enameled any traces of tallow on the zinc would render the same unable to hold the paint or enamel for any length of time, which consequently cracked or scaled off, thereby resulting in the production of an inferior product. In order to overcome this difficulty every trace of the tallow had necessarily to be washed oil the surface of the zinc carefully by means of a solvent, such as gasoline, naphtha or the like. Obviously, this entailed considerable an expense and trouble, together with loss of time but heretofore it has been the only known means of producing zinc sheets upon which any paint or enamel applied thereto would remain permanently.

It is an object, therefore, of the present invention to provide a method of rolling a sheet zinc which overcomes the necessity of using tallow as a means for preventing the zinc from sticking to the rolls.

A further object of the invention is the provision of means whereby the lubricant used between the rolls and the sheet zinc will not need to be washed off before any paint or enamel is applied to the zinc.

A still further object of the invention is Serial No. 403,765.

the provision of meansfor improvements in rolling sheet zinc whereby the lubricant used will form an'oxidized film on the surface of the zinc which will tend to more securely retain any paint or enamel applied thereto.

Other and further important objects of this invention will be apparent from the disclosure "in the accompanying specification.

The invention (in a preferred form) is hereinafter more fully described.

The process is as follows:

In the rolling of zinc the metal is preheated to the desired temperature, and then put through the rolls several times, in the same direction, the distance between the rolls being gradually narrowed.

This is repeated until the sheet of zinc has been reduced to the required thickness.

It is during this rolling operation that the S liability of the zinc to stick upon the rolls occurs and which has heretofore been prevented by the use of a thin film of tallow upon the rolls. However, in order to eliminate the undesirabililty of the tallow as used in this manner, I have conceived the idea of using a semi-drying or a drying oil, such as raw or boiled linseed oil, cottonseed oil or the like.

The lubricant, preferably linseed oil, or cotton seed oil, is applied to the rolls only occasionally and then inonly a very thin film, usually six' or eight sheets of metal being rolled before another application of the oil is needed, this of course being determined by a slight sticking of the zinc to the rolls which becomes readily noticeable to the experienced workman.

It has been found that the use of linseed oil in place of tallow in this respect eliminatesthe sticking of the metal to the rolls and results in the production of a film of oxidized oil over the surface of the sheets of zinc which material aids in the adhesion of paint or enamel to the zinc. A slight excess of heat in the rolls or the metal makes no difference in the action of the oil, for even if a slight decomposition of the oil occurs, causing a few black streaks to show upon the zinc owing to the free carbon, this has no bad effect upon the paint and the paint will adhere very firmly to the zinc.

It is thought that the tallow, being composed mostly of the stearates which are undecomposable at the temperature of the Ill ill)

rolling of the zinc, is retained in its original form upon the sheets of zinc after cooling and thereby acts to prevent the sticking of paint or enamel upon the zinc. However, the linseed oil, being in such thin lilms and being also decomposable at a lower temperature than that of tallow, is oxidized and converted into a thick oil at this temperature and especially with the free access of air owing to the thin film in which the oil is distributed. Some polymerization also takes place which forms a varnish due partly to the heat and also to the effect of dry air and which is very marked in this case, which aids to thicken the oil and forms an elastic skin, which, however being extremely thin is hardly noticeable, but its effects are very apparent in so far as the sticking of the subsequently applied paint or enamel is concerned.

It will be seen that herein is provided an improvement in the methods of rolling sheet Zinc which eliminates all the diificulties which were heretofore due to the use of tallow upon the heated rolls which were used forming the sheets of Zinc. After the sheets of zinc have been turned out from the rolling mills by this improved method, they are all ready to be painted or enameled and there is no delay or consequent expense due to expensive materials and laborious cleaning operations to remove the tallow from the same.

I am aware that numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted otherwise than necessitated by the prior art.

I claim as my invention:

1. In the process of rolling zinc sheets, applying a drying oil to prevent sticking oi the metal to the rollers.

2. In the process of rolling zinc sheets, applying a vegetable oil to prevent sticking of the metal to the rollers.

8. In the process of rolling zinc, applying linseed oil to prevent sticking of the metal to the rollers.

I. In the process of rolling zinc sheets, applying a lubricant between the rollers and the metal which subsequently aids in the retention of paint or enamel on the zinc.

5. A method of rolling zinc sheets, in which a lubricant is applied which does not subsequently prevent the adhesion of paint or enamel to the metal.

6. In the process or" rolling sheet metal, applying a drying oil to prevent adhesion of the metal to the rollers.

7 In the process of rolling sheet metal, applying a vegetable oil to prevent sticking of the metal to the rollers.

S. In the process of rolling sheet metal, applying linseed oil to prevent sticking or the metal to the rollers.

In testimony whereof I have hereunto subscribed my name.

OSCAR GERLACH. 

